I'd like to see

  *this is bold*
  /this is italics/
  _this is underlined_

Beyond simple conventions like this, I'd just as soon drop into HTML as deal with some other markup that ends up being just as complex. We don't need to allow permutations and combinations such as bold and italics, double-weight bold, etc. these never occur in normal prose typesetting and if you need it just use HTML for those rare cases.

Underlining is an emphasis hack for mechanical typewriters or in handwriting. There's no reason to use it typographically in something which has all the layout possibilities of a modern computer or printer.

https://practicaltypography.com/underlining.html

Except to indicate something new and modern which needs its own visual distinction… like hyperlinks. Using underlining as the default for hyperlinks was genius.

Purely anecdotal but I always waste a second clicking something I believed was a link because it was underlined.

> Underlining is an emphasis hack for mechanical typewriters or in handwriting. There's no reason to use it typographically in something which has all the layout possibilities of a modern computer or printer.

The argument presented by that link is valid for paragraphs and valid for printed content.

On a website, underlining single words or short phrases doesn't make them less unreadable, it draws attention to them.

Like with hyperlinks; the displayed form of `[See here](http://here.com) for more inform` is undeniably better than simply `see here for more info` and leave the reader guessing which of those words is the text and which is a hyperlink.

The problem is exacerbated on mobile where the reader cannot hover a mouse over the words to determine which words are a link and which are not.

If you're writing a full paragraph like this:

"Our previous stories of FooBarFactory Inc were well-received by our readers. Investigative Journalism has always been a core principle of PotatoNews. The images and video that our beloved readers shared on Twitter are only a single component in the fight against big corps polluting our environment."

In the above paragraph, "previous stories" is a link, "FooBarFactory" is a link, "well-received" is a link, "images and video" is a link, "Twitter" is a link and "Polluting out environment" is a link.

The advice from Practical Typography would render that entire paragraph free of any indication that there's more for the user to read.

As a point of order;

\* more than 3\/4's of people may not feel that way, particularly those discussing snake\_case Vs CamelCase

That’s PascalCase, camelCase does not capitalize the first word.

Turns out that it's a contentious topic:

https://en.wikipedia.org/wiki/Camel_case

FWIW I use the same nomenclature as you, but that doesn't make it universal.

New rule needs ~ when * or _ is used inside words, so your example wouldn't need escaping. E.g.,

dis~/cuss/~ing

with a similar caveat for 'obvious' fractions and divisions?

You mean ¾?

Only if you can do that for, say, 937\/997.

937⁄997

You need U+2044 FRACTION SLASH.

I honestly had no idea you could do that in Unicode with arbitrary values. Thank you.

This is what Org mode does. It's still very tied to Emacs, but there's an effort to standardize the Org format. Hopefully this will help its adoption outside of Emacs, it's a nice markup (and a lot more).

"why /usr/bin/vi" turns /usr/bin into italic ?"

underlines is not used enough to take the commonly used character ~this is fine~, trailing tilde is rare enough